Omar Khayyam (Persian: عمر خیام), (born 1048 AD, Neyshapur, Iran—1123 AD, Neyshapur, Iran), was a Persian polymath, mathematician, philosopher, astronomer and poet. He also wrote treatises on mechanics, geography, music and was a physicist.

He has also become established as one of the major mathematicians and astronomers of the medieval period. Recognized as the author of the most important treatise on algebra before modern times as reflected in his Treatise on Demonstration of Problems of Algebra giving a geometric method for solving cubic equations by intersecting a hyperbola with a circle. He also contributed to calendar reform and may have proposed a heliocentric theory well before Copernicus. His significance as a philosopher and teacher, and his few remaining philosophical works, have not received the same attention as his scientific and poetic writings. Zamakhshari referred to him as “the philosopher of the world”. Many sources have also testified that he taught for decades the philosophy of Ibn Sina in Nishapur where Khayyam lived most of his life, breathed his last, and was buried and where his mausoleum remains today a masterpiece of Iranian architecture visited by many people every year. Outside Iran and Persian speaking countries, Khayyam has had impact on literature and societies through translation and works of scholars. The greatest such impact was in English-speaking countries; the English scholar Thomas Hyde (1636–1703) was the first non-Persian to study him. However the most influential of all was Edward FitzGerald (1809–83) who made Khayyam the most famous poet of the East in the West through his celebrated translation and adaptations of Khayyam's rather small number of quatrains (rubaiyaas) in Rubaiyat of Omar Khayyam.